I've been searching for answers using the search function but get a lot of non-responsive search hits. Perhaps someone can point me to a thread that I can get my answers. I really did try searching.

2013 F150 XLT, 5.0 DOHC

DRL's are not on, and I want them on. Dealer says "Perhaps, but we'll just hook it up and figure out how to do it." I don't want to pay him to learn how to do it, so If I could print out the instructions and take it to him I might save some money.

I replaced the 265/60 18 Michelin LTX A/S with 255/70 18 Michelin LTX M/S2 for three reasons: Availability, Price ($154 ea), performance reviews for wear, noise, and traction in inclement wx. But now my speedometer is off by about 3.5mph at 60. I'd like to tell the ECM/BCM/TCM the new tire size, but again, the dealer says "Perhaps, but ..."

If anyone can help, thanks in advance.
PS: I don't want to buy a programmer. I have the Ford Extended Service Plan 5/75K. 52K on it now.

 

Hi Greg, I think it's amazing how knowledge is NOT shared among dealerships. My dealership in the little town of Star Valley, AZ had no trouble whatsoever turning on the DRL circuit in my 2014 truck. It was a flash to the ECM and took about 10 minutes. They charged me about $50 for the service, which may have been more than others have paid elsewhere, but in my opinion it was worth it.

I can't tell you any specifics though. Possibly. you might have a different dealership in your area that is more knowledgeable?

Regarding updating the ECM for a different tire size, I thought it could be done by a dealer, but glc posted a short while back that this was not something that could be changed by a dealership flash and that you'd need a programmer to do it. So..., you may be out of luck.

Sorry I can't be more help.

- Jack

 

Dealerships can correct for a limited range of tires and axle ratios. Basically, if it was an option they can do it.

 

IDS ( Integrated Diagnostic System ) - Standard, OEM Tire Size (PCM) = ___NOTE: IDS cannot update/change the wheel diameter for 2015 F-150s.
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